few generator questions

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few generator questions

Postby rlphoto » Mon Sep 26, 2005 9:14 am

Hi Guys, The Walden is almost finnished. we are going to try a maiden voyage this weekend. I will try to post some pics this week of the finnished product. This design is really super so far.

Now about the generator,

I want to buy a small generator not nessasarily for camping but will probably use it some for camping. I want something that I can also run the photo business computers and printers here at the house along with the well pump. but not at the same time. The well pump draws 8.8 amps at 110 volt. This is 1056 watts. I would imagine that it needs double this to start.

The computer equipment I need to run would not exceed what the well pump needs to run.

I would like to get a small minimum 2000 watt model, so it is compact and easy on gas. That way I can take it camping.

The other thing is the condition of the power. I doubt if the well pump is that particular, but the computers will be a lot different. I notice that the more expensive models are of an inverter design?

Maybe I could buy a cheaper generator and get a seperate voltage conditioner?

Anybody wanna comment?

Randy
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Postby GeorgeTelford » Mon Sep 26, 2005 9:28 am

I would check out the well pump thoroughly, it may take Over twice its running current to start, there is also power factor to allow for (some appliances need more power to be available else they will not run, they do not actually use any of this extra power but will not run without it being available)

Generators running electronics, hmm its the start up spikes that ruin stuff, ie they should never be connected to an appliance until the engine as settled and disconnect before shutting genny down, of course invertor-gennies will keep things safer.

The big question is what do you want to run while camping? Most times I find that the camper as no reason to need a genny.

For the house it sounds like a solar or wind system (both) would be better, using a small genny to run a charger as and when needed
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Postby rlphoto » Mon Sep 26, 2005 9:32 am

GeorgeTelford wrote:The big question is what do you want to run while camping? Most times I find that the camper as no reason to need a genny.


Just want to stay on topic. I would not take it camping unless It was an emergency type camping trip, like escaping from a natural disaster or a terrorist attack.

Randy
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Postby rlphoto » Mon Sep 26, 2005 9:52 am

Power conditioner link....

http://tinyurl.com/bb4l7

Generator link

http://tinyurl.com/bq647


How about this combo?
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Postby bdosborn » Mon Sep 26, 2005 8:36 pm

I don't think a conditioner is going to help you much. The issue is starting the pump. Motors take 5-7 times their running current to start. A pump can be especially hard to start because you're starting the pump as well as the motor. Now that doesn't mean you need a generator that's 5-7 times the size of your motor as the generator engine has intertia and the alternator can support short surges to start motors. I'd check with the manufacturer as to whether the generator will start a pump of your size. Every generator has a different combination of alternator and engine size so they all have different capacities. We have a generator sizing program we use at work to model the start requirements, but, its doesn't go below 15kW.
Bruce

Oops, should have read your post more closely- you want to run your photo equipment as well. That will be tough as there will be a good voltage dip every time the pump starts. We try and keep voltage dips to around 5% for sensitive electronic loads and most generators will dip to 30% before stalling. You'll probably want something larger than the 2kW generator. I'd put the line conditioner on it as well as UPSs on the electronics. I haven't used the one you posted a link to so I don't know how good it is. The line conditioner guys are notorious for smoke and mirror specs anyways. Printers are difficult loads for generators as they inject a lot of harmonics on to the line. I probablly wouldn't run it off the generator.

I looked at the specs for the line conditioner and it doesn't give a line regulation spec. But, a general rule of thumb for evaluating lower end conditioners is - How good is the warranty to replace damaged equipment?
Last edited by bdosborn on Mon Sep 26, 2005 8:51 pm, edited 2 times in total.
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Postby madjack » Mon Sep 26, 2005 8:43 pm

...a thought.......a 2000 watt Honda will run you a grand, a 5000 watt jobsite generator will run you 500/750 bucks and is designed to run hi-amp motors, has a larger gas tank and will run 8/9 hrs on a fill up...it's just noisier, something that is fixable
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Postby Chris C » Mon Sep 26, 2005 9:01 pm

I don't know, Madjack. I've got a 5,000 watt generator and I had a lawnmower shop put TWO mufflers on it and we still couldn't tell the difference...........even though they said THEY could.

Hey!By the way, glad to hear from you. I've been worried. Guess I can patch the holes in the knees of my jeans now. :lol:
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Postby Arne » Tue Sep 27, 2005 5:13 am

Don't know if cash is an issue, or what the pump draws on startup.. but Honda makes a setup where you can connect 2 eu2000 generators together for home use, then take one if you want to go camping... so you'd have 4k at home and 2k on the road.
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Postby rlphoto » Tue Sep 27, 2005 6:43 am

Thanks for all the suggestions. Just for the record I will not be running my well pump and computers at the same time I would just start the pump to fill up the pressure tank then shut it off, unless I was washing a load of clothes or taking a shower. No point in having the generator run if I am not using water. I would shut down my computers before pumping water.

The verdict is that I really need 2 generators. A job site one for the pump and misc household use, and a small inverter job for the electronics. The pump is more importaint than the office in the short term. So I will forget about running my office for the time being. I may never need it anyway.

An inverter job big enough for the pump would be $2000+ a waste of money in my opinion.

Here is a link for inverter generators..

http://www.robinamerica.com/generators/index.lasso#

Good reading also.

Now what size for the well pump? If it draws 1000 watts I am guessing 3000 watts to start since it has to pump water while starting. I guess this rules out the 5hp models. I guess I will need 8hp. Wow. The smaller the better. D you guys think a 5 Hp would do it? Most of them are around 2000 watts.

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Postby bledsoe3 » Tue Sep 27, 2005 7:02 am

Here's a 3000 watt generator with a 5.5 HP engine.
http://cgi.ebay.com/Generator-YAMAHA-EF ... dZViewItem
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Postby Arne » Tue Sep 27, 2005 7:03 am

The startup draw is a good question to ask of the pump mfgr, or someone who installs these things..... go to the source.
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Postby asianflava » Tue Sep 27, 2005 2:16 pm

It may be written on a placard mounted to the pump motor.
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Postby Arne » Tue Sep 27, 2005 3:09 pm

If it's a deep well submersible pump, you don't want to go there/g/..... but, if you know the model, you can probably find out easily enough.
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Postby rlphoto » Tue Sep 27, 2005 4:24 pm

The well pump draws 8.8 amps at 110 volt. This is 1056 watts. 4.4 at 220volt. It is a 3/4 hp deep well jet pump. Which means that it is above ground in the basement.

Things that I have read say that to figure 2-3 times the running wattage.

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Postby GeorgeTelford » Tue Sep 27, 2005 6:28 pm

Hi Randy

I have found that generally the manufacturers dont actually know what power is required to startup, where normal mains is available its not really an issue and they dont tend to keep data for weirdos who want to run via Invertor's or Generators.

One of the big problems is that Invertor (and Genny) manufacturers over rate their products, so a 1000 watt genny may only be capable of 1000 watts for 1 minute, its 24/7 rating may only be 750 Watts and oh BTW if the ambiant temperature is above 10C then actually it will only cope with 500W continous.

Also some manufacturers quote Kva which is actually a power factor adjusted figure. Thats why I love Sterling products its the only manufacturer who actually quotes true figures, If you buy a Sterling 500w Invertor it will run 500w 24/7 at any temperature up to 40 Deg Centigrade ! It will also power 2 to 3 times its continous power for start up's.
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